"... the attribution to Henry Louis Mencken, a prominent newspaperman and political commentator during the first half of the 20th century, is accurate. Writing for the Baltimore Evening Sun on 26 July 1920, in an article entitled “Bayard vs. Lionheart” (and reprinted in the book On Politics: A Carnival of Buncombe), Mencken cynically opined on the difficulties of good men reaching national office when the scale of their campaigns precluded them from directly reaching out to large segments of the voting public ..."ref: H. L. Mencken ‘Moron’ Quote, Did H. L. Mencken write that eventually 'the White House will be adorned by a downright moron'?, Snopes.
Aw, shucks go on over to read 'The White House will be adorned by a downright moron', Baltimore Sun, November 19, 2016.
Heck, even Secretary of State Rex Tillerson thinks the White House is adorned by a moron.
ref: Kaitlan Collins, Barbara Starr, Jeff Zeleny, Elizabeth Landers and Kevin Liptak, Tensions escalate after Tillerson calls Trump 'moron', CNN Politics, updated 8:07 AM ET, Thursday, October 5, 2017.
This morning, Republican Senator Bob Corker wrote on Twitter, "It's a shame the White House has become an adult day care center. Someone obviously missed their shift this morning." (8:13 AM - 8 Oct 2017)
ref: Corker Answers Trump's Endorsement Tweet By Calling The White House A 'Day Care', NPR Politics, October 8, 2017, 2:30 PM ET.
I am of the opinion that Henry Louis Mencken couldn't have been more correct when he wrote that article entitled “Bayard vs. Lionheart” for the Baltimore Evening Sun back on July 26,1920.
(However, I do not care for nor do I condone the use of the word "moron.")
For some bonus reading, take a look-see at H. L. Mencken Quotes from BrainyQuote.